His 48-year-old wife disputes his claims, and says he has hidden assets abroad totalling as much as £2 billion.

Earlier this month, he was jailed for six months by a judge at the High Court for repeatedly refusing to reveal his finances.

The judge said the “fixer” had committed a “flagrant and deliberate” contempt of court.

But he claims that the sentence is totally out of proportion to the crime and said it was a “black day” for justice.

“I'm sharing a cell with a complete stranger and have nothing but a bunk bed and lavatory to look at,” Young told the newspaper.

“Luckily I've managed to lose 5lb by being able to workout in the prison gym which has saved my sanity.”

The father-of-two claims his fortune disappeared after a Moscow property deal collapsed three years ago.

Last November, a judge ordered him to reveal details of his finances which he failed to do claiming that his wife’s behaviour had made him ill.

Young, who represented himself at a High Court hearing in London, said he had "done everything in my power".

But lawyers representing Mrs Young argued that her husband, who has been compared to the character in Brewster’s Millions for the speed in which he lost his fortune, had given the court the "runaround".

Mr Justice Moor committed him to prison.

Young, who is said to count Sir Philip Green, the retail entrepreneur, and Boris Berezovsky, the Russian oligarch, among his friends, was worth £400 million in 2006 but was made bankrupt over a £1.8 million debt.

He and his wife, who once owned properties around the world, separated in 2006 after 11 years of marriage and became embroiled in a bitter and long drawn-out divorce battle.

While Young was pleading poverty, he seemed to be living a life "consistent with considerable wealth" and had been "posing with some supermodel or another, drinking champagne, while his wife is being evicted," said Edward Fitzgerald QC, representing Mrs Young.

Young said he had been supporting himself by relying on friends and former business associates and has been given "gifts" to cover rent and living expenses, the court heard.